A percentile compares. It does not grade.

Calculate a height percentile using age, sex, and recorded height.

What does height percentile mean?

If a recorded height is at the 40th percentile, about 40 out of 100 children and adolescents of the same age and sex in the WHO reference are shorter. The other 60 are taller. The number describes the reference, not a mark out of 100.

What the 50th percentile means

The 50th percentile is the median. In the reference, about half of children that age and sex are shorter, and about half are taller. It is a middle value, not a target you are supposed to hit.

What the 5th, 25th, 50th, 75th, and 90th percentiles mean

These are places in the same reference, not steps of growth completed. The 5th percentile means about 5 out of 100 in the reference are shorter. The 25th means about 25 out of 100 are shorter. The 90th means about 90 out of 100 are shorter. Each is a comparison. None is a pass, a fail, or a health label.

What does the 75th percentile mean?

The 75th percentile means about 75 out of 100 children and adolescents of the same age and sex in the WHO reference are shorter, and about 25 are taller. It is not 75 percent of adult height, and it is not 75 percent of growth completed. A person can be at the 75th percentile at one age and at a different percentile later.

A percentile is not a grade

Schools use grades to say whether work met a standard. A height percentile does not do that. People are spread across the reference, and a lower or higher number is still a comparison. It does not say that someone should be taller.

It compares against a reference population

The reference is WHO 2007 height-for-age data for ages 5–19, not the other students in one classroom and not a prediction of adult height. The height calculator applies that reference to a height you enter. The growth charts draw the curves, and growth science explains the z-score behind the percentile.

The height percentile article walks through the same comparison, including what the 50th percentile is and is not. How to read a growth chart shows where a percentile sits among the curves. One percentile is a single comparison. A series of measurements can show whether later heights stay in a similar part of the reference. The growth velocity calculator describes the change between two of those heights.

To calculate a height percentile for one recorded height, age, and sex, use the height percentile calculator.